When using a lighting device to illuminate an area it is often found necessary to change the profile of the projected light to match the object to be illuminated. When using a conventional hand held flashlight for example often the flashlight is equipped with a means for changing the profile of the emitted light from a spot to a wash. When using a conventional reflector and a single light source the reflector is often moved in relative position to the source to accomplish changing the profile. U.S. Pat. No. 4,987,523 to Lindabury discloses an illumination device that moves the lamp in relative position to the reflector.
U.S. Pat. No. 4,855,884 to Richardson discloses a variable beamwidth stage light with a single light source, relying on an axially movable reflector for changes in beamwidth. The reflector is constructed of a plurality of reflective leaves that are moved by a motor to change the focal length of the reflector. When working with a plurality of light sources, various methods have been disclosed that enable the multiple light sources to be converged or diverged. U.S. Pat. No. 4,729,070 to Chiu discloses an adjustable ring for concentrating multiple beams of light. Chiu discloses an apparatus for changing the angle of incidence of a plurality of light sources arranged in a ring. A threaded holder surrounds the ring of light sources while a cam mechanism adjusts the angle of the light sources that is operated by turning the threaded holder. U.S. Pat. No. 5,752,766 to Bailey et al. discloses a multi-color focusable LED stage light. A linear actuator is operable to move a base member containing an array of LEDs which in turn cause the LED array to change the direction of the optical axes of a substantial number of LEDs. By deforming the base member 20 in Bailey, the LEDs can be converged or diverged on an area to be illuminated.
The Bailey patent does not discuss the issues of thermal management. High intensity light emitting diodes (LEDs) have a critical upper temperature operating limit. This can easily be exceeded when the LEDs are arranged in-groups as in the Bailey patent and the ambient air temperature rises.
Multiparameter lights of the prior art utilize a single light source with motors to vary the focus, color, position and intensity. U.S. Pat. No. 3,845,351 to Ballmoos et al. titled: METHOD AND APPARATUS FOR THE ADJUSTMENT OF A PLURALITY OF FLOODLIGHTS discloses a number of floodlights especially for the illumination of a stage or studio, in which the parameters azimuth, elevation, brightness, focus and color of a bundle of light rays of each floodlight are adjusted to an optimum value for any one of a plurality of lighting effects.
U.S. Pat. No. 4,392,187 to Bornhorst titled: Computer controlled lighting system having automatically variable position, color, intensity and beam divergence illustrates another example of the prior art. Each of the instruments houses a central lamp and an optical system designed to collimate the light from the lamp and vary the parameters of the light by inserting motor driven optical components into the light by remote control.
Multiparameter lights are generally controlled by a central control system via a serial data communications system. An operator operating the central control system may control each multiparameter light separately to adjust the parameters. Each multiparameter light may be provided with a communications address so that each multiparameter light may be addressed separately by an operator operating the control system
Multiparameter lights of the prior art are depicted in the High End Systems Product Line 1997 brochure.